Instnjctions): The Biostatistics and Clinical Core will provide the leadership and expertise needed to support the laboratory and clinical researeh ofthe 4 Projects ofthis SPORE grant. The Clinical component will be led by Dr. Prados, who will interact with Project leaders to develop clinical trials based upon laboratory investigations in Projects Three and Four in particular, as well as to discuss results in Projects One and Two that may lead to relevant biomarkers and potential stratification factors for future or potential clinical trials. The Clinical component will support the actual conduct of SPORE clinical trials, including providing clinicians, research nurses and data coordinators, and assist in all of the required regulatory reporting for those studies. Dr. Prados will support and facilitate the interactions of Project leaders with CTEP, cooperative groups, biopharmaceutical, and industry groups to obtain new therapeutic agents appropriate to the design of new studies that come from Projects Three and Four, as well as supporting the conduct of SPORE clinical trials to those groups as needed. The Biostatistical component wilt be led by Dr. Molinaro, who will interact on an ongoing basis with the individual leaders from all four Projects to assess the statistical needs of each. The Biostatistical component will provide: advice on the design of experimental and clinical studies, including calculating sample sizes and power; data analysis support (either by performing the analyses within the core or advising qualified personnel within the projects), including the use of appropriate statistical models and applications of statistical test; and, when necessary, the development of novel methods to help interpret results from experiments. Additionally, a member of the Biostatistical component will participate in regularly scheduled project meetings to provide statistical/bioinformatics input and assist in preparing the necessary materials for presentation and publication. RELEVANCE (See instructions): The primary aim of a SPORE grant is to support translational research that leads to clinical trials and ultimately improved outcome for patients. This Core will support the efforts of 4 Projects designed to study the biology, incidence, and epidemiology of brain tumors (high grade and low grade) using those results to